Wind direction from wind components

In meteorology, the wind direction is defined as the direction the wind is coming from. If we got a South wind direction that means that the wind is coming from the South and going to the north. Also, it is expressed by degrees from the true north (0°), so the east direction is 90°, the…

A (friendly) guide to install WRF-Chem

In a way, WRF-Chem can be easy to run (you don’t need to recompile each new simulation), but it could be difficult to install. Especially, if you don’t have experience working on Linux or building executables through compilation. That was my case. Here I want to show the steps I followed to install WRF-Chem, and…

Errors with netcdf when compiling WRF-Chem tools: mozbc, anthro_emiss, and bio_emiss

When performing an air quality simulation, we usually need to include chemical boundary conditions, anthropogenic emission, and biogenic emissions. To add those inputs in WRF-Chem, we have the mozbc, anthro_emiss, and bio_emiss WRF-Chem tools. mozbc can include BC from global models like CAM-Chem and WACCM, anthro_emiss can be used to build emissions from EDGAR emission…

Functions and loop to make multiple plots

Subplots in R: Comparing pollutants from different stations

Here we use subplots in R to compare the concentration of two pollutants from two air quality stations (AQS) by plotting 2 subplots instead of one plot per pollutant measured in each AQS. We do it using R base graphics and using par(), especially playing with inner and outer margins. Help came from this post…

A concentration points map with R

When we got the pollutant concentration for each air quality station from a network, It is very useful to plot them on a map. It will give us an insight into the pollutant spatial distribution and answer questions like: Where is the highest concentration of X? In downtown or in the suburbs?  Is there transportation…

Change language in openair timeVariation plot labels

I’m a big fan of openair package, and I frequently use its plotting capabilities for quick data analysis and reports. I study in Sao Paulo, and sometimes the plots have to be in Portuguese and others in English. For example, sometimes I got plots with the name of the days in Portuguese, but the xlabel…

Plotting lines (or segments) in R

The task is to plot a street network based on information of the its segements. That is, each segment has and start point (x1, y1) and an end point (x2, y2).  By using google earth , I retrieved some coordinates from Paulista Avenue and some intersection streets, we are gonna used the segments and also…

Heatmaps in R: an example using ozone concentrations

Here we want to answer how Ozone is transported from the Metropolitant area to the surroundings. For that, we chosen five stations that measure ozone in Sao Paulo State and that are align like the predominant wind in this zone: southeasterly .Then, we’ll  see at what time, during the day, they register the highest ozone…

My most frequent vim commands to (pre)process raw text data

Here are my most used vim commands to edit raw text data to be ready to be feed in other languages like R or python 1. Display the tabular data formatted (:set nowrap) 2. Go to the last line (On the keyboard press) 3. Go to any line (n = line number). For example to…